title: Ferroelectric control of a Mott insulator.
abstract: The electric field control of functional properties is an important goal in oxide-based electronics. To endow devices with memory, ferroelectric gating is interesting, but usually weak compared to volatile electrolyte gating. Here, we report a very large ferroelectric field-effect in perovskite heterostructures combining the Mott insulator CaMnO3 and the ferroelectric BiFeO3 in its "supertetragonal" phase. Upon polarization reversal of the BiFeO3 gate, the CaMnO3 channel resistance shows a fourfold variation around room temperature, and a tenfold change at ~200 K. This is accompanied by a carrier density modulation exceeding one order of magnitude. We have analyzed the results for various CaMnO3 thicknesses and explain them by the electrostatic doping of the CaMnO3 layer and the presence of a fixed dipole at the CaMnO3/BiFeO3 interface. Our results suggest the relevance of ferroelectric gates to control orbital- or spin-ordered phases, ubiquitous in Mott systems, and pave the way toward efficient Mott-tronics devices.
authors.affiliation: 1] National Institute of Advanced Industrial Science and Technology (AIST), Higashi 1-1-1, Tsukuba, Ibaraki 305-8562, Japan [2] Unité Mixte de Physique, CNRS-Thales, 1 Av. Augustin Fresnel, Campus de l'Ecole Polytechnique, Palaiseau 91120, France, and Université Paris-Sud, 91405 Orsay, France.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Yamada
authors.forename: Maya
authors.initials: M
authors.lastname: Marinova
authors.forename: Philippe
authors.initials: P
authors.lastname: Altuntas
authors.forename: Arnaud
authors.initials: A
authors.lastname: Crassous
authors.forename: Laura
authors.initials: L
authors.lastname: Bégon-Lours
authors.forename: Stéphane
authors.initials: S
authors.lastname: Fusil
authors.forename: Eric
authors.initials: E
authors.lastname: Jacquet
authors.forename: Vincent
authors.initials: V
authors.lastname: Garcia
authors.forename: Karim
authors.initials: K
authors.lastname: Bouzehouane
authors.forename: Alexandre
authors.initials: A
authors.lastname: Gloter
authors.forename: Javier E
authors.initials: JE
authors.lastname: Villegas
authors.forename: Agnès
authors.initials: A
authors.lastname: Barthélémy
authors.forename: Manuel
authors.initials: M
authors.lastname: Bibes